1. Field of the Invention
This invention relates to a spacer assembly and method for stacking steam table trays and more particularly to such a spacer assembly and method wherein the trays are positioned and secured in a compact fashion prior to still or agitation heat processing within a retort.
2. Description of the Prior Art
Alternatives to round can food packing have been sought for sometime. The shape of round cans precludes convenient storage without waste of considerable storage space. The round can shape also requires a considerable length of time for heating the contained foodstuffs within the can to carry out a heating process providing commercial sterility, or heating prior to use. With the current emphasis on energy conservation, it becomes increasingly important to provide prepared foodstuffs which require minimal energy expenditure in accomplishing heating for processing, cooking or heating preparatory to serving.
Sealed pouches and sealed trays such as the half size steam table tray have been recently introduced into the food service market and smaller trays are envisioned which will be introduced to the consumer market in the near future. The sealed pouches and trays are generally introduced into retorts where hot water is passed around the pouch and tray surfaces to provide commercial sterility and to cook the contained ingredients prior to storage or distribution. The pouches are generally confined between two plates while the hot water is passed over the plates and around the pouches to perform the cooking operation within the retort. The plates are carried in cars which are rolled into the retort prior to the initiation of the cooking process. The steam table trays, on the other hand, are usually laid in a first layer on the floor of a retort car, and metal strips are laid on top of the first layer. An additional layer of trays is put down on top of the metal strips to separate the additional layer from the first layer so that the hot cooking water may pass therebetween. Additional metal strips are then laid down on top of the additional layer of steam trays followed by another layer of steam trays and so on until the car is filled. When the car is thereafter rolled into the retort, the door closed and the hot cooking water introduced thereto, the trays tend to shift position to the detriment of the integrity of the trays seals which receive sharp blows during such shifting. Moreover, the trays may be dented, and the lower layers of trays often are found to have faulty seals after the cooking process due to the excessive weight of the trays stacked thereabove which is born entirely by the lower layers of trays. The trays are generally fabricated from a steel material which is coated prior to filling with foodstuffs to protect the steel, thereby reducing the tendency of the trays to rust and prolonging the shelf life of the filled and processed trays, and this coating is easily damaged under conventional tray heating processes.